2. Questions Bank
  3. JEE Main & Advanced
  4. Mathematics
  5. Determinants & Matrices

JEE Main & Advanced Mathematics Determinants & Matrices Question Bank Types of matrices, Algebra of matrices

  • question_answer
    If \[A=\left[ \begin{matrix}    3 & 1  \\    -1 & 2  \\ \end{matrix} \right]\], then \[{{A}^{2}}=\] [Karnataka CET 1994]

    A) \[\left[ \begin{matrix}    8 & -5  \\    -5 & 3  \\ \end{matrix} \right]\]

    B) \[\left[ \begin{matrix}    8 & -5  \\    5 & 3  \\ \end{matrix} \right]\]

    C) \[\left[ \begin{matrix}    8 & -5  \\    -5 & -3  \\ \end{matrix} \right]\]

    D) \[\left[ \begin{matrix}    8 & 5  \\    -5 & 3  \\ \end{matrix} \right]\]

    Correct Answer: D

    Solution :

    \[A=\left[ \begin{matrix}    3 & 1  \\    -1 & 2  \\ \end{matrix} \right]\] \[{{A}^{2}}=A.A=\left[ \begin{matrix}    3 & 1  \\    -1 & 2  \\ \end{matrix} \right]\,\left[ \begin{matrix}    3 & 1  \\    -1 & 2  \\ \end{matrix} \right]\] \[{{A}^{2}}=\left[ \begin{matrix}    8 & 5  \\    -5 & 3  \\ \end{matrix} \right]\].


You need to login to perform this action.
You will be redirected in 3 sec spinner